Floods, droughts and storms have dramatically increased over the past decades as global temperatures and carbon dioxide levels have risen.

A study by the Institute for Environmental Studies at Amsterdam University, released in London yesterday, says that the effects of climate change are already being felt in death and destruction as storms become more violent and frequent.

The number of such extreme events has been increasing steadily. There were 14 in the 1950s, and 16 in the 1960s, rising to 29 a decade later. By the 1980s there were 44 weather related disasters and in the past decade 70.

The big insurance companies found that only six of the 40 worst insured losses between 1970 and 1999 were not weather related. Swiss Re, one of the world's biggest reinsurance companies, calculates that even taking inflation, population growth and increased global wealth into account, economic losses due to natural disasters doubled in the 20 years after 1970.

Jennifer Morgan, director of WWF Climate Change Campaign, which commissioned the report, said: "The risk of destabilising the earth's climate system is growing every day. Time is not on our side."

Among examples in the report are two winter storms in Europe in 1999 which caused insured damage totalling £3bn and flooding along the Yangtze river in 1998 that caused 4,000 deaths and losses of £20bn.